Quoting Sowjanya Komatineni (2019-05-28 16:08:48)
> This patch implements peripheral clock context save and restore
> to support system suspend and resume operation.
Again, why?
> diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c
> index 6f2862eddad7..08b788766564 100644
> --- a/drivers/clk/tegra/clk.c
> +++ b/drivers/clk/tegra/clk.c
> @@ -81,6 +81,10 @@ static struct clk **clks;
> static int clk_num;
> static struct clk_onecell_data clk_data;
>
> +#ifdef CONFIG_PM_SLEEP
> +static u32 *periph_ctx;
> +#endif
Please move this into the ifdef below.
> +
> /* Handlers for SoC-specific reset lines */
> static int (*special_reset_assert)(unsigned long);
> static int (*special_reset_deassert)(unsigned long);
> @@ -210,6 +214,65 @@ const struct tegra_clk_periph_regs *get_reg_bank(int clkid)
> }
> }
>
> +#ifdef CONFIG_PM_SLEEP
> +void tegra_clk_periph_suspend(void __iomem *clk_base)
> +{
> + int i, idx;
> +
> + idx = 0;
> + for (i = 0; i < periph_banks; i++, idx++)
> + periph_ctx[idx] =
> + readl_relaxed(clk_base + periph_regs[i].rst_reg);
> +
> + for (i = 0; i < periph_banks; i++, idx++)
> + periph_ctx[idx] =
> + readl_relaxed(clk_base + periph_regs[i].enb_reg);
> +}
> +
> +void tegra_clk_periph_force_on(u32 *clks_on, int count, void __iomem *clk_base)
> +{
> + int i;
> +
> + WARN_ON(count != periph_banks);
> +
> + for (i = 0; i < count; i++)
> + writel_relaxed(clks_on[i], clk_base + periph_regs[i].enb_reg);
> +}
> +
> +void tegra_clk_periph_resume(void __iomem *clk_base)
> +{
> + int i, idx;
> +
> + idx = 0;
> + for (i = 0; i < periph_banks; i++, idx++)
> + writel_relaxed(periph_ctx[idx],
> + clk_base + periph_regs[i].rst_reg);
> +
> + /* ensure all resets have propagated */
> + fence_udelay(2, clk_base);
> + tegra_read_chipid();
> +
> + for (i = 0; i < periph_banks; i++, idx++)
> + writel_relaxed(periph_ctx[idx],
> + clk_base + periph_regs[i].enb_reg);
> +
> + /* ensure all enables have propagated */
> + fence_udelay(2, clk_base);
> + tegra_read_chipid();
> +}
> +
> +static int tegra_clk_suspend_ctx_init(int banks)
> +{
> + int err = 0;
> +
> + periph_ctx = kzalloc(2 * banks * sizeof(*periph_ctx), GFP_KERNEL);
Is this kcalloc(2 * banks, sizeof(*periph_ctx)... ?
> + if (!periph_ctx)
> + err = -ENOMEM;
> +
> + return err;
> +}
> +#endif
> +
> struct clk ** __init tegra_clk_init(void __iomem *regs, int num, int banks)
> {
> clk_base = regs;
> @@ -226,11 +289,20 @@ struct clk ** __init tegra_clk_init(void __iomem *regs, int num, int banks)
> periph_banks = banks;
>
> clks = kcalloc(num, sizeof(struct clk *), GFP_KERNEL);
> - if (!clks)
> + if (!clks) {
> kfree(periph_clk_enb_refcnt);
> + return NULL;
> + }
>
> clk_num = num;
>
> +#ifdef CONFIG_PM_SLEEP
Can you use if (IS_ENABLED(CONFIG_PM_SLEEP)) here?
> + if (tegra_clk_suspend_ctx_init(banks)) {
> + kfree(periph_clk_enb_refcnt);
> + kfree(clks);
> + return NULL;
> + }
> +#endif
> return clks;
> }
>
